Are the sliders icons of science fiction? To the world at large, no. But that doesn't mean they aren't or can't be iconic. As a quartet, the sliders are larger than life figures who embody an idealized vision of human potential and represent the belief that ideas and ingenuity can solve any problem. Within Seasons 1 - 2, nearly every dilemma is resolved by cleverness, improvisation and the ability to put concepts into practice.
The claim that icons need "a clearly defined ethos" or a "prime directive" or "some other thing that defines their objectives" is little more than exclusionary, claiming what an icon isn't without any idea of what it is. Icons are not made by ticking off checkboxes.
An icon defines a genre, format or form of storytelling, becoming immortalized in memory and identified with that genre. Indiana Jones is an icon of adventure stories because the character is supremely well-suited to the genre in imagery and application. Luke Skywalker is an icon of space opera, Sherlock Holmes is an icon of detective fiction, etc..
The sliders are in some ways genre defiant in that they can fit into any kind of story, any format, any genre. They can be the stars of the story or they can die in the first shot. They can be supporting players, the protagonists, the villains, the establishment or the rebels.
I would say that the sliders are somewhat paradoxical in that they are icons of the science fiction anthology format -- a format that usually doesn't have regular characters. The icons of this genre, before SLIDERS, were Rod Serling's narrator in THE TWILIGHT ZONE and the Control Voice of THE OUTER LIMITS. However, the SLIDERS storytelling engine allows for the show to have the same range as an anthology and the characters are ideally suited to being plugged into any kind of story.
You have scientific brilliance with Quinn and Arturo and interpersonal brilliance with Wade and Rembrandt. You have age and wisdom in Rembrandt and Arturo and youth and innocence in Quinn and Wade. You have cynical conservatism in Arturo and counter-cultural revolution in Rembrandt; you have daring and bravado in Quinn matched with compassion and empathy in Wade. There's no limit in how you use them; if you can't use the main version of the characters, you just use doubles that week.
The other part of the SLIDERS iconography is that the characters *look* memorable; they are costumed and coiffed in ways that make them distinct and recognizable in any lighting and angle. You have the flannel and jeans and hair of Quinn Mallory, the eccentric dressiness of Wade, the stout and broad figure of Arturo and the lean and ostentatiously clothed Rembrandt with his absurd suits.
As a quartet, they stand out in silhouette. The image of the four sliders in shadow running towards us is one of the most vivid TV images of the 1990s and completely in tune with the sliders: distant, aloof figures on the edge of infinity, but when we get closer, we see that they are complex and conflicting human beings.
Also, all four have highly distinctive speech patterns thanks to both the Season 1 - 2 writers and the actors who played them; as a pastiche writer, I found that all four voices lent themselves beautifully to prose-approximations of the onscreen characters.
Mulder and Scully, despite the simplistic definition of being the believer and the skeptic, are just as muddy and contradictory as the sliders; "The Truth is Out There" and "Trust No One" are rarely accurate to the show from which they originate. They don't have distinctive costumes. They don't have a prime directive they haven't violated or an objective they haven't failed at or undermined. Mulder and Scully are the sliders' contemporaries -- Jerry O'Connell and David Duchovny played basketball together in Vancouver. Yet, Mulder and Scully are icons while the sliders are barely remembered. Why?
Very simply, THE X-FILES was successful. It was well-marketed, had high viewing figures, was strongly merchandised, and managed to make it seven seasons before it starting losing original cast members. It had a strong following of both diehards and casual viewers. As a result, Mulder and Scully are the definitive supernatural-procedural characters and achieved pop cultural iconography and immortality.
In contrast, SLIDERS made it all of one season split across two years with a massive hiatus after the first nine episodes followed by three seasons that are impossible to reconcile with the Pilot episode. The show failed to embed itself in the popular consciousness because it was frequently incoherent and often unwatchably poor. But the characters in the first twenty-two episodes transcend all that.
They're icons to me. To me, Quinn Mallory is one of the greatest fictional characters ever created and he stands next to Batman, Spock, Sherlock Holmes and Dr. House. I accept that they're not icons to the public, but aside from popularity, they fulfill the basic requirement: they define a genre and format (sci-fi anthology) and are ideally suited to that genre and format. And I don't think anyone should be declaring that iconography is off limits to the sliders just because they themselves don't see it.